Dust Scrubber

ABSTRACT

A dust scrubber for a mining shearer machine is adapted to be mounted behind the rear surface of the shearer arm, on the opposite side of the arm to the mine surface being cut, so as to extract airborne particulates. The scrubber may be mounted to the shearer via a compensation mechanism such as a double hinge and link arrangement which maintains relatively static position and/or orientation of the scrubber despite the pivoting of the shearer arm in operation.

This application is a divisional of U.S. Ser. No. 13/254,481, filed Nov.30, 2011, which is a national stage entry of international applicationserial no. PCT/AU2010/000244, filed Mar. 3, 2010, which claims priorityfrom Australian application serial no. 2009900913, filed Mar. 3, 2009,and Australian application serial no. 2009905581, filed Nov. 16, 2009,all of which are hereby incorporated by reference herein in theirentireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to dust removal for use in mining andother dusty workplace environments, and especially to dust suppressionarrangements for use in conjunction with a mining shearer device tosuppress dust generated.

2. Description of Related Art

Respirable dust is a health hazard to those working in the dustyenvironment, is a cause of respiratory complaints, and presents otherdangers by limiting visibility by the workers. Because of this,workplace rules specify maximum permissible dust concentrations and/orexposures.

One activity which generates a considerable amount of dust in a confinedspace is mining, one form of which is the long wall mining techniqueoften used for coal extraction.

Long wall mining involves the driving of a pair of parallel gate roads,referred to as the maingate and the tailgate, in the plane of themineral ore seam, the gate roads being spaced apart by a distancereferred to as the long wall. A mining machine, known as a shearer, thenmines the coal face in the long wall by cutting the long wall in adirection transverse to the gate roads. The coal is extracted placed onan armoured conveyor and then conveyed to the maingate, fed into acrusher and then deposited on a rubber conveyor belt which carries thecoal out of the mine. Support and drive means for the mining machine canbe mounted in the gate roads.

The shearer machine has a shearer body which extends generally parallelto the long wall coal face, with a pivot joint at one end to a shearerarm supporting the shearer drum which performs the cutting. The drum isgenerally cylindrical and is driven to rotate about its axis, which isperpendicular to the face.

The position of the drum on the coal face is swept up and down bypivoting of the shearer arm relative to the shearer body, whilehorizontal movement across the long wall face is performed by movementof the shearer body.

Respirable dust may be produced by the cutting operation or as the longwall shearer machine moves forward or by associated operations in themine. Ventilation is provided to maintain an air flow along the longwall to help reduce dust problems, but this is often insufficient on itsown to meet appropriate standards and further measures are required.

U.S. Pat. No. 4,251,567 discloses a cowl-like dust scrubber fitted tothe shearer drum at its trailing side to capture dust generated by thecutting operation, incorporated into or attached to the cowl whichusually resides at that location.

SUMMARY OF THE INVENTION

The present invention seeks to provide an alternative dust suppressionarrangement.

In one form, the invention provides a dust scrubber which is adapted tomount to the shearer arm, so as to be located at a side of the arm whichfaces away from the mine surface to be cut.

A first form of the invention provides a dust scrubber for suppressingdust generated by mining shearer of the type which includes a shearerarm having a front face proximal to a mine surface to be cut and arotating shearer drum supported at the front face of the shearer arm,the dust scrubber including a housing having an inlet, an outlet and apassage between the inlet and the outlet, an extraction fan for drawingan air stream containing dust particles into the scrubber and throughthe housing passage, and particle extraction means for removingparticles from the air stream, wherein the dust scrubber is adapted tobe mounted to the shearer arm so as to remove airborne particlesgenerated by operation of the shearer drum.

A further form of the invention provides a mining shearer and dustscrubber combination comprising a long wall mining shearer including ashearer arm having a front face proximal to a long wall mine surface tobe cut and a rotating shearer drum supported at the front face of theshearer arm; and a dust scrubber as described herein.

In a further form, the invention provides a dust suppression arrangementfor a mining shearer which comprises a movable shearer arm attached to ashearer body, the arrangement including a dust suppression unit mountedto the shearer by mounting means which at least partially compensatesfor movement of the shearer arm relative to the shearer body.

In one preferred form, the mounting arrangement includes a double hingearrangement which acts to keep orientation of the dust suppression unitrelatively steady upon pivoting of the shearer arm relative to theshearer body.

Further forms of the invention will be apparent from the description,and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Further preferred embodiments of the invention will now be describedwith reference to the accompanying drawings, in which:

FIG. 1 shows a dust scrubber according to a first preferred embodiment,mounted to a long wall mine shearer;

FIG. 2 is a more detailed view of the scrubber of FIG. 1 mounted to theshearer arm;

FIG. 3 shows the scrubber of the first embodiment separated from theshearer arm;

FIGS. 4A to 4D are respectively isometric, plan, end and rear views ofthe scrubber of FIG. 3;

FIGS. 5A to 5D are respectively isometric, plan, end and rear views ofthe inlet and a filter/contact chamber housing portion of the scrubber;

FIGS. 6A to 6C are respectively plan, front and end views of the fanhousing and outlet housing portion of the scrubber of FIG. 3;

FIG. 7 is an isometric view of a scrubber according to a secondpreferred embodiment, having a modified outlet diverter hoodconfiguration;

FIG. 8 shows a dust scrubber and mounting arrangement according to asecond embodiment of the invention;

FIGS. 9A to 9C is a series of rear views of a miner shearer arm and dustscrubber of FIG. 8, with the shearer arm pivoted between raised, neutraland lowered positions;

FIGS. 10A to 10C are isometric views of the arrangement of FIG. 9A to9C, in similar positions.

Where shown, dimensions are in millimetres.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The invention is described herein for use in long wall mining, in whichthe face 10 a mineral seam (usually coal) is mined by a shearer machine12 having a shearer body 14 with a series of pivot cleats 16 at one end,and a shearer arm 18—usually L-shaped—with mating pivot cleats 20 on apivot arm portion 22 of the shearer arm and a main arm portion 24 whichextends parallel to the face of the seam.

The shearer arm main portion carries on its front face a generallycylindrical shearer drum 26, which has teeth (not shown) for cuttinginto the coal face as it is rotated. The drum is driven by a drivemechanism (not shown) inside the shearer arm to cut coal from the face,which is then collected and transported by conveyor to the surface.

The shearer drum is moved across the coal face in the horizontaldirection by moving the shearer body, whilst the height of the drum onthe coal face is varied by pivoting of the shearer arm about a pivotaxis 28 through the cleats 16, 20.

Operation of the shearer generates a great deal of dust, which impedesvisibility and is a health hazard to workers in the vicinity.

In order to help suppress this dust, a dust scrubber 30 is mounted tothe shearer arm. In the first illustrated embodiment of FIGS. 1 and 2,the scrubber 30 is mounted at the rear of the main arm portion 24 of theshearer arm 18, i.e. on the opposite side of the arm from the shearerdrum 26. In the first illustrated embodiment, the scrubber housing ismounted to both the main arm portion 24 and the pivot arm portion 20,fitting into the 90 degree internal corner between these parts.

The scrubber 30 may be mounted by any suitably convenient and robustmeans; bolting of the scrubber housing to the shearer arm is preferred.

As can be seen in FIG. 1, the scrubber may be adapted for fitting of thewater spray unit 32 which would normally be fitted to the shearer arm inthis position.

With reference to FIGS. 2, 3 and 4A to 4D, the scrubber 30 housing has agenerally rectangular section inlet 34 which opens to the bottom, withwater spray nozzles 36 adjacent the inlet to spray a fog of waterdroplets out into the dust-laden air stream which is being drawn intothe inlet to promote intimate contact between the dust particles in theair and the water spray.

The air stream passes upwards into the inlet, then the passage withinthe housing turns 90 degrees into a rectangular, horizontalfilter/contact chamber portion 38 of the housing which runs parallel tothe main arm portion 24 of the shearer arm 18, in the direction towardsthe shearer body.

The filter/contact chamber 38 may optionally include a rectangularfilter plate 40 (shown in ghost in FIGS. 5B and 5D) across the air flowpath. The filter plate 40 may of the type formed of one or more layersof a metal mesh contained within a frame, or any another suitable type.Preferably, the filter is of the wet type, with the housing alsocontaining internal water spray nozzles (not shown) directed onto thesurface of the filter plate to wash the filter.

Alternatively, the filter/contact chamber can be an open chamber inwhich the contact between the dust particles and water droplets in theair stream is continued.

FIGS. 5A to 5D show the housing inlet 34 and filter/contact chamber 38,including curved vanes 42 in the filter/contact chamber 38 to promotesmooth air flow into the next 90 degree bend in the air passage, intothe fan housing 44, described below.

The cylindrical fan housing portion 44 extends parallel to the pivot armportion of the shearer arm, generally perpendicular to the coal face 10,and houses a fan 46 for drawing air into and through the scrubberhousing. The fan 46 (shown in ghost in FIGS. 6A and 6C) is preferablycapable of generating high flow volumes through the scrubber, forexample from 1 to 10 m³/s, more preferably about 3-7 m³/s, mostpreferably about 5 m². Preferably, the fan is fluid-driven, for examplehydraulically actuated.

The number and profile of the fan blades, and the speed at which the fanis driven, may be varied to achieve the desired pressure and flowcharacteristics, as known per se.

The air stream then passes into the outlet chamber 48, where it isguided by curved vanes 50 to pass vertically into an outlet lid 52,which is contoured to direct the outlet air flow with entraineddust/water mixture back over the top of the shearer body 14, away fromthe workers.

Air flow through the scrubber is preferably balanced by keeping the airpassage cross sectional area approximately equal between the inlet,contact chamber and outlet sections, for example at approximately 0.1 m²to 0.3 m², for example about 0.2 m².

As seen from FIGS. 5A to 6C, the scrubber housing may be formed in anumber of sections—for example the inlet and contact chamber portion(FIGS. 5A to 5D), the fan and outlet housing (FIGS. 6A to 6C) and thehinged outlet lid 52, assembled by bolting or other means which allowsdisassembly for servicing.

The scrubber housing may be formed of any suitably robust material, forexample of welded and/or bolted steel sections, and may include mountingblocks for attachment of the housing to the shearer arm as previouslydescribed.

The housing may also include a connection block (not shown) forattachment of water supply for the scrubber and hydraulic fluid fordriving the fan,

FIG. 7 shows an alternative outlet lid 152 which is contoured to divertthe outlet stream over the shearer body but with direction components inthe upwards and forward (i.e. in the direction towards the coal face)directions, so as to reduce the spray of the dirty water exiting thedevice coming into contact with the workers.

FIGS. 8, 9A to 9C and 10A to 10C illustrate an alternative embodiment,in which a dust suppression unit—shown here as a dust scrubber 130—ismounted to the pivoting shearer arm in a manner which keeps the positionand/or orientation of the dust suppression unit relatively stabledespite raising and lowering of the shearer arm 118 relative to theshearer body 114.

The dust scrubber shown in FIGS. 8 to 10C is a modified version of thatdescribed and shown in respect of FIGS. 1 to 7.

Compared to the dust scrubber of FIGS. 1 to 7, the scrubber of FIGS. 8to 10C is modified so that it draws in air at an inlet 134 at its end,and ejects the outlet air flow with entrained dust/water mixture forwardunderneath the main arm portion 124 of the shearer arm 118, i.e. backtowards the coal face.

The operation of the dust scrubber is generally similar to thatdescribed above in relation to the first embodiment, including theinclusion of inlet spray nozzles 136, an internal fan and optional wetfilter arrangement (not shown).

Also similar to the first embodiment, the scrubber is mounted to theshearer arm so as to be located behind the main arm portion 124, so thatit draws dust-laden air from behind the rear face of the shearer mainarm, on the opposite face to the shearer drum.

The mounting arrangement of the scrubber however varies from the firstembodiment, in that it is mounted via a hinge arrangement to the shearerarm so as to maintain a relatively static position and/or orientationcompared to the shearer body despite up and down movement of the shearerarm in use.

The illustrated mounting arrangement comprises a double hingearrangement which has upper 160 and lower 162 hinges connecting threehinge plates in a generally Z arrangement, and a flexible link 164 suchas a chain, cable or similar ligature extending between respectivemounting lugs or other attachment means on the top of the scrubbercasing and the shearer body. The link 164 may hinge over the cover ofthe pivot arm portion 122 of the shearer arm.

As can be seen in FIGS. 9A to 9C and 10A to 10C, when the shearer arm isgenerally horizontal (FIGS. 9B and 10B), the double hinge is closed sothat the scrubber is also horizontal.

When the shearer arm is pivoted up (FIGS. 9A and 10A), it can be seenthat the lower hinge falls open under gravity to the extent allowed bythe chain, to keep the scrubber relatively horizontal. Likewise, whenthe shearer arm is pivoted down (FIGS. 9C and 10C), it can be seen thatthe chain pulls upper hinge to keep the scrubber relatively horizontal.

In this way, the orientation of the scrubber is kept relatively stabledespite movement of the shearer arm, so that the dust extractionperformance is less affected.

The mounting arrangement may also be used for mounting of other dustsuppression equipment, for example sprays, to a shearer arm in a mannerwhich provides compensation for movement of the shearer arm.

In this specification, the word “comprising” is to be understood in its“open” sense, that is, in the sense of “including”, and thus not limitedto its “closed” sense, that is the sense of “consisting only of”. Acorresponding meaning is to be attributed to the corresponding words“comprise, comprised and comprises where they appear.

While particular embodiments of this invention have been described, itwill be evident to those skilled in the art that the present inventionmay be embodied in other specific forms without departing from theessential characteristics thereof. The present embodiments and examplesare therefore to be considered in all respects as illustrative and notrestrictive, the scope of the invention being indicated by the appendedclaims rather than the foregoing description, and all changes which comewithin the meaning and range of equivalency of the claims are thereforeintended to be embraced therein. It will further be understood that anyreference herein to known prior art does not, unless the contraryindication appears, constitute an admission that such prior art iscommonly known by those skilled in the art to which the inventionrelates.

I/We claim:
 1. A dust suppression arrangement for use with a miningshearer which includes a movable shearer arm attached to a shearer body,the dust suppression arrangement comprising: a dust suppression unit anda mounting for mounting the dust suppression unit to the shearer arm,the mounting including a compensation mechanism that adjusts at leastone of position and orientation of the dust suppression unit relative tothe shearer arm responsive to movement of the shearer arm relative tothe shearer body.
 2. A dust suppression arrangement according to claim1, wherein: the compensation mechanism includes a double hingearrangement which acts to maintain orientation of the dust scrubber unitrelative to the shearer body generally static irrespective of pivotingmovement of the shearer arm relative to the shearer body.
 3. A dustsuppression arrangement according to claim 2, wherein: the compensationmechanism further includes a flexible link between the dust suppressionunit and the shearer body so as to actuate the double hinge arrangement.4. A dust suppression arrangement according to claim 3, wherein: theflexible link is a fixed length link.
 5. A dust suppression arrangementaccording to claim 3, wherein: the flexible link is a chain.
 6. A dustsuppression arrangement according to claim 2, wherein: the double hingearrangement comprises three hinge plates in a generally Z-shapedarrangement and a pair of generally horizontal hinges.
 7. A dustsuppression arrangement according to claim 6, wherein: the double hingearrangement comprises a first hinge plate attached to the shearer arm, asecond hinge plate attached to the dust scrubber unit, and anintermediate hinge plate connected to said first hinge plate via agenerally horizontal first hinge and connected to said second hingeplate via a generally horizontal second hinge.
 8. A dust suppressionarrangement according to claim 7, wherein: the compensation mechanismfurther includes a flexible link between the dust scrubber unit and theshearer body so as to actuate the double hinge arrangement, wherein saidflexible link causes said first hinge to open up when the shearer arm ispivoted below horizontal.
 9. A dust suppression arrangement according toclaim 8, wherein: said flexible link allows said second hinge to open upto a limited extent when the shearer arm is pivoted above horizontal.10. A dust suppression arrangement according to claim 1, wherein: saiddust suppression unit is a dust scrubber for removing airborne particlesfrom a region behind the shearer arm.
 11. A dust suppression arrangementaccording to claim 1, wherein: the compensation mechanism acts tomaintain at least one of position and orientation of the dust scrubberrelative to the shearer body generally static.
 12. A mining apparatuscomprising: a mining shearer which includes a movable shearer armattached to a shearer body; and a dust suppression arrangement accordingto claim
 1. 13. A mining apparatus comprising: a mining shearer whichincludes a movable shearer arm attached to a shearer body; and a dustsuppression unit and a mounting for mounting the dust suppression unitto the shearer arm, the mounting including a compensation mechanism thatadjusts at least one of position and orientation of the dust suppressionunit relative to the shearer arm responsive to movement of the shearerarm relative to the shearer body.